Orthopedic plating assembly for bone fixation and subsidence

ABSTRACT

Orthopedic plating assemblies and methods for bone fixation that include an orthopedic plate and orthopedic anchors that can accommodate subsidence in the vertebral bodies as well as prevent the anchors from “backing out” of their installed position. The orthopedic anchors may be capable of rotating and translating with respect to the plate, and the plate may be able to translate after being fastened to the vertebral bodies.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/510,156 filed Oct. 9, 2014, which is a continuation of U.S.application Ser. No. 12/698,412 filed Feb. 2, 2010, now U.S. Pat. No.8,882,814, the contents of which are incorporated by reference herein intheir entireties for all purposes.

FIELD OF THE INVENTION

The present invention is generally directed to an orthopedic platingassembly used for bone fixation and subsidence. In particular, thepresent invention relates to a plating assembly capable of blockingorthopedic anchors to prevent the anchor from disengaging or dislodgingfrom the orthopedic implant.

BACKGROUND

Whether to treat degenerative disease, traumatic injury, or defect,congenital or otherwise, surgical reconstructions of bony elements arecommon procedures in current medical practice. Regardless of anatomicalregion or the specifics of the reconstructive procedure, many surgeonsemploy orthopedic devices or implants to adjust, align and maintain thespatial relationships of adjacent bones or bony fragments duringpostoperative osteosynthesis. With respect to surgical reconstruction inthe spinal region, it is known to employ orthopedic plates to adjust,align and maintain the spatial relationship of adjacent vertebral bodiesto promote postoperative fusion. It is further known to attach theorthopedic plate to the vertebral bodies using orthopedic anchors whichact to share the load and support the bone and orthopedic plate asfusion progresses.

In some cases, subsidence occurs in the bone or bone fragments to whichthe orthopedic plate and anchors are attached. The definition ofsubsidence in terms of spinal biomechanics is the sinking of theorthopedic plate and anchors having a higher elasticity modulus in oneor more vertebral bodies characterized by a lower elasticity modulus,resulting in changes of the spinal geometry. Any excessive subsidencedecreases the interbody space and produces both local and generalkyphotization of the spine which can cause destabilization of thescrew-plate and/or screw-bone interfaces (e.g. pulling-out, alteredangulation or breakage of the screws).

In addition, notwithstanding the forces resulting from subsidence, overtime, it has also been found that as a result of the forces placed uponthe orthopedic device and anchors resulting from the movement of thespine, the orthopedic anchors can begin to back out from their installedposition eventually resulting in the anchors disconnecting from thedevice.

As such, there exists a need for an orthopedic plate and anchors thatcan accommodate subsidence in the vertebral bodies as well as preventthe fasteners from “backing out” of their installed position.

SUMMARY

In one embodiment, the present invention provides an orthopedic platingassembly for bone fixation that includes an orthopedic plate andorthopedic anchors that can accommodate subsidence in the vertebralbodies as well as prevent the anchors from “backing out” of theirinstalled position. The assembly, in one embodiment, includes anorthopedic plate and at least one orthopedic anchor, the orthopedicanchor capable of rotating and translating with respect to the plate.The assembly further includes a first blocking member and a secondblocking member, the blocking members cooperate to prevent the at leastone orthopedic anchor from uninstalling from an installed position.

Further areas of applicability of the present invention will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating the preferred or exemplary embodiments of the invention, areintended for purposes of illustration only and are not intended to limitthe scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a partial perspective view of one embodiment of an orthopedicplating assembly;

FIG. 2 is a partial cross-sectional side view of the orthopedic platingassembly of FIG. 1;

FIGS. 3A-3C are schematic top views of the assembly shown in FIG. 1showing the orthopedic anchor in various positions with respect to theorthopedic plate; and

FIG. 4 is a perspective view of the orthopedic plating assembly of FIG.1.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

The following description of the preferred embodiment(s) is merelyexemplary in nature and is in no way intended to limit the invention,its application, or uses.

With reference to FIGS. 1-4, an embodiment of an orthopedic platingassembly 10 is illustrated. Although the assembly 10 is shown isolatedfrom the environment it would typically be used in, it should beunderstood that the assembly 10 provides a bone fixation and/or fusionsolution with an orthopedic plate and orthopedic anchors that canaccommodate subsidence in the vertebral bodies and can prevent theanchors from “backing out” of their installed position via an anchorblocking system. Further, it should be understood that the assembly 10,although disclosed as being used on the spine with respect to vertebralbodies, can also be used on any appropriate bony anatomical region andwith any appropriate reconstructive procedure.

The assembly 10 preferably includes an orthopedic plate 12 and at leastone anchor 14 having a head portion 16, a shank portion 18, and threads20 that surround at least a portion of the shank portion 18. The headportion 16, preferably, is, at least in part, generally spherical andincludes an opening 17 for receiving an instrument capable of engagingand driving the anchor 14 into bone tissue 1. Although only one anchoris discussed, as shown in FIG. 1, two anchors 14 can be included in theassembly and it is further contemplated that the assembly 10 can includeany number of anchors.

In a preferred embodiment, as shown in FIG. 4, the plate 12 includescarriage plates 13 at one or both ends of the plate 12. The carriageplates 13 include at least one opening 15 for receiving an anchor 14.The openings 15 are preferably configured and dimensioned to approximatethe dimensions of the head portion 16. This dimensioning of openings 15will permit the anchors 14, when in an installed position, to rotate ina poly-axial fashion with respect to the carriage plate 13 providingrigid fixation of the carriage plate 13 to the anchor 14 and bonetissue. Furthermore, although captured in the slots 11 of plate 12, thecarriage plates 13 can slide with respect to the plate 12 allowing theplate 12 to translate after being fastened to the bone tissue 1.

In a preferred embodiment, the plate 12 also includes at least oneopening 22 for each anchor 14. The openings 22 are elongated, as bestseen in FIG. 1, permitting the anchors 14, when in an installedposition, to translate and rotate in a poly-axial fashion with respectto the plate 12. This translatability and rotational freedom coupledwith the slidable carriage plates 13 provides additional functionalityas the assembly 10 can continue to function effectively even under bonesubsidence conditions. For example, if subsidence were to occur in thevertebral bodies to which the assembly 10 has been fastened, the plate12, the carriage plate 13, and anchors 14 can move with respect to eachother, in a rotational as well as translational fashion, to accommodatethe subsidence without destabilizing the anchor-plate and/or anchor-boneinterfaces. Alternatively, it is also contemplated that the openings 22,rather than being elongated, can be configured and dimensioned toapproximate the dimensions of the head portion 16. This dimensioning ofopening 22 will prevent the anchors 14 from translating but will stillpermit the anchors 14 to rotate in a poly-axial fashion with respect tothe plate 12 providing rigid fixation of the orthopedic plate 12 to theanchor 14 and bone tissue 1.

In a preferred embodiment, the assembly 10 also includes a blockingmechanism 24. The blocking mechanism 24 preferably is comprised of twocomponents that cooperate to block the anchors 14 from backing out orotherwise disengaging from the orthopedic plate 12 after installation ofthe assembly 10. The first component is a blocking screw 26 having anenlarged head 28. It is contemplated that there will be at least oneblocking screw 26 adjacent each opening 22 and each opening 15. In apreferred embodiment, the head 28 includes a cutout 30 and an opening 32for receiving an actuation instrument. As discussed further below, theorientation of cutout 30 with respect to the opening 22 and opening 15will determine whether the head 28 is in a blocking position or anon-blocking position. Although the blocking screw 26 is shown as beinga set screw, any mechanism that would serve as a blocking mechanism iscontemplated, such as a cam type mechanism or a slidable interferencemechanism.

The second component is a blocking plate 32. As shown in FIGS. 1, 2 and4, the blocking plate 32 is preferably removable connected to the plate12 and is shaped and dimensioned to block at least a portion of at leastone opening 22. In a preferred embodiment, as best seen in FIG. 4, itcan be seen that there is one blocking plate 32 for each pair ofelongated openings 22. The blocking plate 32 is connected to the plate12 via a screw. Preferably, both the blocking plate 32 and the screw 34have a low-profile thereby not increasing the overall thickness of theorthopedic plate 12. The blocking plate 32 can be installed prior to theintroduction of the anchors 14 or can be installed after the anchors 14have been installed through the openings 22.

In an exemplary use of the assembly 10 as shown in FIG. 4, the plate 12is placed on or near the area of treatment. The anchors 14 are installedthrough the openings 15, 22 from a first uninstalled position to asecond installed position where the anchors 14, in the installedposition, engage the plate 12 and the carriage plate 13 as well as theanatomy in the area of treatment to secure the plate 12 in place. Withrespect to the anchors 14 that are installed through the openings 15,after the anchors 14 are installed in place, the blocking screw 26 ismanipulated via opening 22 so that the enlarged head portion 28 blocksanchor 14 from backing out or from moving in an direction opposite fromthe direction of installation. This is accomplished by moving the cutout30 from facing the opening 22 to a position where the cutout 30 is notfacing the opening 22. With the cutout 30 oriented away from the opening15, there is no longer enough room for the anchor 14 to pass backthrough the opening 15 thereby preventing the anchors 14 from “backingout.”

With respect to the anchors 14 that are installed through the openings22, as best seen in FIG. 3A, the anchors 14 are installed throughportions of the openings 22 that are not covered by the blocking plate32. After the anchors 14 are installed in place, the blocking screw 26is manipulated via opening 32 so that the enlarged head portion 26blocks anchor 14 from backing out or from moving in a direction oppositefrom the direction of installation. This is accomplished by moving thecutout 30 from facing the opening 22 to a position where the cutout 30is not facing the opening 22. This position of cutout 30 can best beseen in FIGS. 3B and 3C. With the cutout 30 oriented away from theopening 22, there is no longer enough room between the head 28 ofblocking screw 26 and the covering plate 32 for the anchor 14 to passthrough. Accordingly, once the anchors 14 are installed in place, themanipulation of blocking screw 26 coupled with the blocking plate 32prevents those anchors 14 from “backing out.” Furthermore, even if theplate 12 were to translate with respect to the anchors 14, as seen inFIGS. 3B and 3C, the anchors 14 will still be prevented from backing outby virtue of the blocking plate 32 covering at least a portion of theopenings 22.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedto be included within the scope of the following claims.

What is claimed is:
 1. An orthopedic plating assembly comprising: anorthopedic plate having at least one opening configured and dimensionedto receive an orthopedic anchor; a first blocking member and a secondblocking member, wherein the second blocking member rests above anuppermost surface of the orthopedic plate; and an orthopedic anchorconfigured to be positioned through the at least one opening, wherein,when in a blocking position, the first blocking member and the secondblocking member cooperate to prevent the at least one orthopedic anchorfrom uninstalling from the orthopedic plate such that the orthopedicanchor is bounded by a sidewall of the first blocking member and abottom surface of the second blocking member.
 2. The assembly of claim1, wherein the first blocking member includes a cut-out portion, thefirst blocking member being rotatable from a non-blocking position tothe blocking position.
 3. The assembly of claim 2, wherein in thenon-blocking position the cut-out portion is configured to face theorthopedic anchor and in the blocking position, the cut-out portion isconfigured to face away from the orthopedic anchor.
 4. The assembly ofclaim 1, wherein the at least one opening is elongated.
 5. The assemblyof claim 1, wherein the orthopedic anchor is configured to pivot andlaterally translate with respect to the orthopedic plate when installed.6. The assembly of claim 1, wherein the orthopedic plate furthercomprises at least one carriage plate, the at least one carriage platehaving at least one opening for receiving at least one additionalorthopedic anchor.
 7. The assembly of claim 6, wherein the orthopedicplate has at least one slot and wherein the at least one carriage plateis slidably received in the slot of the orthopedic plate.
 8. Theassembly of claim 7, wherein the at least one carriage plate is capturedin the slot of the orthopedic plate.
 9. The assembly of claim 7, whereinthe at least one carriage plate has at least one blocking member havinga blocking position and a non-blocking position.
 10. The assembly ofclaim 1, wherein the first blocking member includes an enlarged headportion and a cutout portion.
 11. The assembly of claim 1, wherein thesecond blocking member is removably connected to the orthopedic plate.12. The assembly of claim 1, wherein the orthopedic anchor has a headportion, a shank portion and threads that surround at least a portion ofthe shank portion, and wherein the head portion is in part spherical andincludes an opening for receiving an instrument capable of engaging anddriving the anchor into bone tissue.
 13. The assembly of claim 1,wherein the at least one opening includes first and second openings, thefirst opening having a first orthopedic anchor positioned therein, andthe second opening having a second orthopedic anchor positioned therein,wherein the second blocking member is a plate configured to block boththe first and second orthopedic anchors.
 14. An orthopedic plateassembly comprising: an orthopedic plate having at least one openingconfigured and dimensioned to receive an orthopedic anchor, a firstblocking member and a second blocking member, wherein the secondblocking member rests above an uppermost surface of the orthopedicplate; and an orthopedic anchor having a head portion, the orthopedicanchor configured to extend through the at least one opening, whereinwhen in a blocking position, a sidewall of the first blocking membercontacts a sidewall of the head portion of the at least one orthopedicanchor and a bottom surface of the second blocking member contacts a topportion of the head portion of the at least one orthopedic anchor. 15.The assembly of claim 14, wherein the at least one opening is elongatedto allow for lateral translation of the orthopedic anchor.
 16. Theassembly of claim 14, wherein the orthopedic plate further comprises atleast one carriage plate, the at least one carriage plate having atleast one opening for receiving a second orthopedic anchor.
 17. Theassembly of claim 16, wherein the orthopedic plate has at least one slotand wherein the at least one carriage plate is slidably received in theslot of the orthopedic plate.
 18. The assembly of claim 17, wherein theat least one carriage plate is captured in the slot of the orthopedicplate.
 19. The assembly of claim 17, wherein the at least one carriageplate has at least one blocking member having a blocking position and anon-blocking position.
 20. The assembly of claim 14, wherein the atleast one opening includes first and second openings, the first openinghaving a first orthopedic anchor positioned therein, and the secondopening having a second orthopedic anchor positioned therein, whereinthe second blocking member is a plate configured to block both the firstand second orthopedic anchors.